MX (a mail exchanger record) is a type of DNS entry or resource record used to specify the mail server responsible for accepting incoming mail sent to a domain name. MX records must always point to a domain, never an IP address.
If there are no MX records for your domain, or if your MX records point to the wrong location, you will not be able to receive emails. So from this point of view, the proper MX configuration is a must to have a faultless receiving mail service.
Typically, you have multiple MX records assigned to your domain name, which can prevent lost email messages during an outage.
MX records are composed of the priority and the mail server’s name.
An example of an MX record can be: 0 mail.example.com
- ‘0’ is the priority.
- The lower that number is, the higher the domain’s priority.
- ‘mail.example.com’ is the mail server it connects to reach your inbox. The actual address varies depending on which company hosts your email.
- Outgoing email servers connect to the MX servers in order of priority.
- If you use more than one MX record with the same priority, it picks one randomly (in effect, load balances the connections).